About Cunda (Ven. Sāriputta’s Passing Away)
Cunda Sutta  (SN 47:13)

On one occasion the Blessed One was staying near Sāvatthī in Jeta’s Grove, Anāthapiṇḍika’s monastery. Now at that time Ven. Sāriputta was staying among the Māgadhans in Nālaka village—diseased, in pain, severely ill. Cunda the novice was his attendant. Then, because of that illness, Ven. Sāriputta totally unbound.

So Cunda the novice, taking Ven. Sāriputta’s bowl & robes, went to Ven. Ānanda in Jeta’s Grove, Anāthapiṇḍika’s monastery, near Sāvatthī, and on arrival, having bowed down to him, sat to one side. As he was sitting there he said to Ven. Ānanda: “Venerable sir, Ven. Sāriputta has totally unbound. Here are his bowl & robes.”

“Cunda, my friend, this news is reason for seeing the Blessed One. Come, let’s go to the Blessed One and report this matter to him.”

“Yes, venerable sir,” Cunda the novice responded to him.

So Ven. Ānanda & Cunda the novice went to the Blessed One and, on arrival, having bowed down to him, sat to one side. As they were sitting there, Ven. Ānanda said to the Blessed One, “Lord, just now Cunda the novice said to me, ‘Venerable sir, Ven. Sāriputta has totally unbound. Here are his bowl & robes.’ It was as if my body were drugged, I lost my bearings, things weren’t clear to me, on hearing that Ven. Sāriputta had totally unbound.”

“But, Ānanda, when he totally unbound, did Sāriputta take the aggregate of virtue along with him? Did he take the aggregate of concentration… discernment… release… the aggregate of knowledge & vision of release along with him?”

“No, lord, when he totally unbound, Ven. Sāriputta didn’t take the aggregate of virtue… concentration… discernment… release… the aggregate of knowledge & vision of release along with him. It’s just that he was my instructor & counselor, one who exhorted, urged, roused, & encouraged me. He was tireless in teaching the Dhamma, a help to his companions in the holy life. We miss the nourishment of his Dhamma, the wealth of his Dhamma, his help in the Dhamma.”

“But, Ānanda, haven’t I already taught you the state of growing different with regard to all things dear & appealing, the state of becoming separate, the state of becoming otherwise? What else is there to expect? It’s impossible that one could forbid anything born, existent, fabricated, & subject to disintegration from disintegrating.

“Just as if the largest limb were to fall off of a great tree composed of heartwood, standing firm; in the same way, Sāriputta has totally unbound from this great Saṅgha of monks composed of heartwood, standing firm. What else is there to expect? It’s impossible that one could forbid anything born, existent, fabricated, & subject to disintegration from disintegrating.

“Therefore, Ānanda, each of you should remain with your self as an island, your self as your refuge, without anything else as a refuge. Remain with the Dhamma as an island, the Dhamma as your refuge, without anything else as a refuge. And how does a monk remain with his self as an island, his self as his refuge, without anything else as a refuge? How does he remain with the Dhamma as an island, the Dhamma as his refuge, without anything else as a refuge? There is the case where a monk remains focused on the body in & of itself—ardent, alert, & mindful—subduing greed & distress with reference to the world. He remains focused on feelings… mind… mental qualities in & of themselves—ardent, alert, & mindful—subduing greed & distress with reference to the world. This is how a monk remains with his self as an island, his self as his refuge, without anything else as a refuge, with the Dhamma as an island, the Dhamma as his refuge, without anything else as a refuge. For those who—now or after I am gone—remain with their self as an island, their self as their refuge, without anything else as a refuge, with the Dhamma as an island, the Dhamma as their refuge, without anything else as a refuge, they will be the foremost of the monks: those who are desirous of training.”

See also: DN 16; MN 44; SN 21:2; SN 22:84; AN 5:49; AN 5:57